This invention concerns snowshoes, especially snowshoes of the type having a suspended boot binding allowing pivoting in a pitch direction, about a transverse axis.
Modern snowshoes typically consist of a binding to hold the user's foot and boot, a crampon or cleat on the underside of this binding to provide traction on snow and ice directly under the boot, and with the binding being on a rotational axis to allow the crampon and binding to rotate along a transverse (pitch) axis. The snowshoes also sometimes include a suspension system that allows the crampon binding assembly to rotate about a longitudinal (roll) axis, or to translate in the vertical direction, or a combination of both, while limiting rotation about a vertical (yaw) axis.
Attachment of such suspension systems to a snowshoe structure requires certain structural characteristics of the snowshoe to support the suspension. This has typically been achieved by using a tubular aluminum frame that extends around the periphery of the snowshoe, as in snowshoes of Atlas Snowshoe Company.
This tubular aluminum frame, while affording a weight effective way of providing the required structure, also has certain limitations in the traction characteristics it can achieve on certain ice or snow surfaces; the round section of the tubing is rather slippery on certain surfaces.
The current invention seeks to overcome these limitations in traction, by affording the structure required to provide binding and crampon suspension through the use of a tubular aluminum frame nose section that extends around a front portion of the periphery of the snowshoe and is capable of fully supporting the binding suspension. This nose section is combined with other configurations for the aft portions of the snowshoe, so that many variations are possible.
Many patents have described attaching a binding to a snowshoe either by mechanically fixing the binding to the snowshoe frame in a rigid type of attachment or by a suspended type of attachment. In both attachment methods different elements have been used to add traction features to the snowshoe. A suspended binding as described herein means one that is supported from a frame or arms using a flexible element which may be tensioned straps, pulling inwardly on the frame or arms as steps are taken in the snowshoe.
Atlas Snowshoe Company suspends a binding from a snowshoe frame in a way that allows the binding to have limited range of motion in two degrees of freedom along the transverse and longitudinal axes, i.e. in pitch and roll. For example, see Atlas U.S. Pat. Nos. 5,440,827 and 5,699,630. This type of suspension also allows the binding to have a limited range of motion in one degree of translation (up/down) in the vertical direction. The suspension of the binding, that is, the springing resistance of the frame to inward pulling by tensioned suspension straps, is supported by the full length of the snowshoe of the surrounding snowshoe frame members, which is a full-circuit peripheral structure. There are elements added to the snowshoe to provide traction while using the snowshoe to travel on different types of snow conditions. These traction elements are added to the snowshoe deck.
Tubbs Snowshoe Company also has a suspended, tensioned type of snowshoe binding attached to the surrounding snowshoe frame. This binding is also supported by the full length of the snowshoe and surrounding snowshoe frame members. The binding has limited range of motion in two degrees of rotation along the transverse and longitudinal axis. This binding can also have one degree of translation in the vertical direction. Traction elements attached to the snowshoe deck provide traction while using the snowshoe on different snow conditions. These are features of Tubbs Snowshoe Venture model snowshoe.
Tubbs Snowshoe Company has a binding which is rigidly attached to the snowshoe, as shown in U.S. Pub. No. 2010/0126046. In this example there is no peripheral snowshoe frame, but instead a plastic snowshoe deck that supports the binding. The binding can rotate in only one degree of freedom along the transverse axis and no degree of translation in any direction. There are elements formed into the plastic deck for traction and there are elements that are attached to the plastic deck to add traction while traveling on different types of snow conditions. The traction elements are placed toward the middle of the snowshoe and not at the outer edges of the snowshoe. This example does not having a suspended binding.
Mountain Safety Research has a snowshoe with a rigidly attached binding, as shown in U.S. Pub. No. 2004/0231200. The binding is rigidly supported by the surrounding snowshoe frame and has a limited range of motion in one degree of freedom along the pitch or transverse axis. The binding has no degree of translation in any direction. The binding is rigidly attached to a cross brace frame member that is attached to the surrounding snowshoe frame, which is essentially a thin metal rail. The snowshoe in this example does not add elements to provide traction while traveling on different types of snow conditions. Instead this snowshoe uses a type of snowshoe frame members that have bottom traction elements on the frame members. This is not a suspended binding.
Salomon U.S. Pat. No. 6,112,436 describes a snowshoe with a suspended binding. The binding is supported by the surrounding snowshoe deck and has a limited range of motion in two degrees of rotation along the transverse and longitudinal axis, provided by articulating mechanical links. The binding in this example has one degree of translation in the vertical direction. The traction elements in this example are provided on the peripheral bottom surfaces of the snowshoe's deck. The snowshoe does not have frame members of the type discussed above surrounding the binding, but is primarily a composite deck made from plastic materials. The support for the suspended binding is provided by the full length of the snowshoe.
U.S. Pat. No. 6,226,899 of Atlas Snowshoe Company describes a snowshoe assembled from multiple pieces, including molded plastic nose and tail pieces and a pair of rails extending between the nose and tail, forming left and right midsection components of the snowshoe. The snowshoe of that patent has a boot binding/cleat assembly afforded pitch rotation via a transverse pivot shaft. The binding is not suspended.